How to watch October’s Orionids meteor shower and contemplate the wonders of the sky

Header image: Orionid meter shower, by Jeff Sullivan, via Flickr

Daniel Brown, Nottingham Trent University

Throughout the year, there are different meteor showers that all have different properties and can be more or less easy to spot.

During October, it’s time for the Orionids, one of the best known meteor showers and also the most reliable. This is also an amazing opportunity to venture outside, observe them yourself and find out what makes them so special.

Shooting stars aren’t actually stars, but are caused by meteoroids. These are essentially rocks travelling in space. They can be similar in size to small pebbles and sand or, in rarer cases, bigger objects.

As our Earth moves through its orbit around the Sun, it can run into these objects by chance. There is a lot of this material hitting Earth: approximately 48 tonnes per day.

As the particles enter our atmosphere, they become meteors. The Orionids have an average speed of about 61 km/s. The interaction with our atmosphere causes them to burn up at high altitude, cause bright streaks in the sky visible for a short time.

Meteor showers, though, are not random encounters with meteoroids. Earth sometimes passes through denser regions of space debris left behind by comets as they travel around the Sun.

Comets are dirty snowballs made of loose material that is held together by frozen gases. When the Earth encounters comet debris, meteors can streak through the sky, putting on a spectacular display.

Each meteor shower is linked to a specific comet. The Orionids are of interest, not because there are lots of meteors, but because they are linked to Halley’s comet. This comet was the first to be recognised as periodic – those with orbital periods around the Sun of less than 200